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Calculus derivitives help me please!?

I'm finding points of max or min by finding first derivitive and factoring

1/4x^4-x^3-2x^2-6

This problem I need points of inflection

X^4+x^3-3x^2-x+1

Please help and thankyou!!

3 Answers

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  • Favorite Answer

    (1/4) * 4 * x^3 - 3 * x^2 - 2 * 2 * x - 0 =>

    x^3 - 3x^2 - 4x =>

    x * (x^2 - 3x - 4) =>

    x * (x - 4) * (x + 1)

    Set that to 0 and solve

    x^4 + x^3 - 3x^2 - x + 1

    4x^3 + 3x^2 - 6x - 1

    12x^2 + 6x - 6

    6 * (2x^2 + x - 1)

    Set that to 0 and solve

  • cidyah
    Lv 7
    8 years ago

    X^4+x^3-3x^2-x+1

    d/dx(x^4+x^3-3x^2-x+1)

    = 4x^3+3x^2-6x-1 = 0

    The point of inflection is the solution of the above equation

    x=1 is a sulution

    x= -1.5931 is a solution

    x =-1.5693 is s solution

    ((www.wolframalpha.com)

  • 5 years ago

    you may desire to prepare the chain rule. This function has 5 nested applications: cos, sqrt, sin, tan, and a linear function (?x). bear in mind that cos' = -sin, sqrt' = a million / (2*sqrt), sin' = cos, tan' = sec^2 or a million + tan^2, and (ax)' = a y = cos?(sin(tan?x)) y' = -sin?(sin(tan?x)) * (?(sin(tan?x)))' = -sin?(sin(tan?x)) * (a million / 2?(sin(tan?x))) * (sin(tan?x))' = -sin?(sin(tan?x)) * (a million / 2?(sin(tan?x))) * cos(tan?x) * (tan?x)' = -sin?(sin(tan?x)) * (a million / 2?(sin(tan?x))) * cos(tan?x) * (a million + tan^2(?x)) * (?x)' = -sin?(sin(tan?x)) * (a million / 2?(sin(tan?x))) * cos(tan?x) * (a million + tan^2(?x)) * ? I flow away any needed simplication to you, yet I do see a ?(sin(tan?x)) in the two the numerator and denominator.

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